Electric fixture



June 4, 1929. J, 'WEBER 1,715,804

ELECTRIC FIXTURE Filed July 26, 19277 7o/w? Weber;

Patented June 4, 1929.

^ UNITED STATES 1,715,804 PATENT oFFicE.

JOHN' WEBER, OF SCHENECTADY, NEW YORK, ASSIGNOR TO WEBER ELECTRIC COM- PANY, OF SCHENECTADY, NEIN YORK, A CORPORATION F NEVI YORK.

ELECTRIC FIXTURE.

Application filed July 26, 1927. Serial o. 208,601.

The present invention relates to electrical fixtures, and more particularly to an attachment or part for electric lamp sockets.

Certain types of electric lamp sockets are provided with a collar or sleeve of ceramic insulating material, such as porcelain, the sleeve or collar being interiorly threaded to engage a threaded metallic part of the socket.

Due to the shrinkageof porcelain and similar materials and the difficulty in determining the shrinkage before the molding operation and in controlling the shrinkage when molding, it is not feasible to form in the porcelain threading of exact predetermined size, and consequently, such sleeves or collars as have heretofore been used are provided with relatively coarse threads to co-act with correspondingly formed threads on a metal part of the socket. Such constructions are unsatisfactory because of the character of the threading and also for the reason that a sleeve or collar of such construction is relatively weak, due to its tendency to fracture when any strain is placed thereon. Moreover, strain upon the threads frequently causes the same to strip.

An object of the invention is to provide an attachment or part for sockets or the like which avoids the above mentioned objections, and is provided with relatively line thread-l and a metallic liner which also serves to reinforce the shell or sleeve of porcelain. These and other objects of the invention will become clearer as the description proceeds in connection with a preferred embodiment shown in the accompanying "drawings, wherein:

Figure 1 is a vertical sectional View of an electric light fixture.

Figure 2 is a top plan view of the attachment or part embodying the present invention.

Figure 3 is a b ottom plan view.

Figure 4 is a side view, and

Figure 5 is a vertical sectional view on the line 5-5 of Figure 3.

Referring to the drawings for a more detailed description, 1() indicates a canopy which may be suitably secured to a wall 11, by any suitable means (not shown). The canopy hasv an interior flange 13 surrounding an opening 14, through which projects the reduced portion 15 of an electric lamp socket 16. The socket is supported upon the flange by means of a ring 17 which engages the shoulder 15 upon the socket shell, and the ring is provided with a suitable socket engaging means such as the integrally formed rip-standing hook 19 which cooperates with a projection extending through the shell from the interior of the socket. In the type of socket illustrated, the projection is an exit 2() fora chain 21, the socket being of the conventional pull type. The socket and supporting ring 17 may be anchored in position by a collar or sleeve 22, which in the present instance cooperates with threads 23 upon the reduced portion 15 of the socket shell. A reflector 24 having a central opening 25 through which the socket portion 15 lits, is clamped by the collar 22 between the same and the interior flange 13 of the canopy.

The collar 22, to which the present invention primarily relates, comprises a'collar-like shell 23 of a suitable ceramic insulating material, such as porcelain, and a threaded liner 27 of metallic material, such as brass, fitting within the shell and substantially confined to the interior of the shell, i. e., not extending to any appreciable extent beyond. the ends thereof. The liner 27 has a flange 28 overlying one end of the shell 26, preferably the end which abuts the canopy iiange 17 so as to protect the shell against abutting engagement, and is suitably anchored to the shell so as to prevent relative movement between the liner and shell. Preferably, the anchoring of the two parts together is obtained by interengaging recesses and projections upon the two parts and the engagement is also preferably effected at opposite ends of the liner whereby to distribute throughout the shell any strain placed upon the shell when the collar is threaded upon the socket.

In the present instance, the flange 28 is provided with downwardly projecting portions 30 which fit in recesses 31 formed in the porcelain. These depressions 31 are formed when the shell is molded, and as illustrated, are arranged in pairs relatively close together to provide an intermediate lug 32, which fits in the space between the closely arranged pairs of projections 31. This interlocking' engagement securely retains the liner against rotative movement in the shell. At the opposite end of the liner, it has portions 33 struck out into grooves or depressions 34 inthe shell, these grooves extending only partly through the shell to provide abutting shoulders 35 which prevent the liner from moving longitudinally of the shell.

The construction described provides a unitary article which is considerably stronger than the conventional sleeve of porcelain in which the threads are fomed in the porcelain itself. As Will be observed, the threads of the liner 27 are relatively fine, Which enables a close fit and tight engagement With the cooperating part upon the socket or other device, and the liner is practically concealed. The flange 28 prevents any engagement of the porcelain shell with a metal part and serves to prevent movement of the liner in one direction through the shell as Well as preventing rotation thereof Within the shell, due to the fact that it is provided with the anchoring projections 30.

Obviously, numerous modications may be made in the structure illustrated and described Without departing :from the invention. It will be understood, of course, that in referring to the shell as being of porcelain, this term as used in the specification and claims is intended to cover any equivalent material of frangible character which is liable to check or break dovvn under severe strains.

I claim:

l. In a device of the class described, an annular collar of porcelain having a smooth interior surface and a metallic threaded liner anchored in said collar by inter-engaging projections and depressions on the liner and collar, said liner overlying said interior surface and having` a flangr` overlying one end of the collar, the remainder of the liner being confined to the interior of the collar.

2. In a device of the class described, an annular collar oit porcelain having a smooth bore and a metallic liner snugly fitting Within and anchored in said collar adjacent opposite ends of the liner by interengaging projections and depressions on the liner and collar, said liner having a flange overlying one end of the collar and the remainder thereof being confined to the interior of the collar.

3. In a device of the class described, a porcelain collar having a smooth bore and a threaded metallic liner anchored in said collar having a flange overlying one end of the collar, said collar and liner flange having inter-engaging parts to prevent relative movement thereof.

4. In a device of the class described, a porcelain collar having an unthreaded bore and a threaded metallic liner snugly fitting Within and anchored in said collar bore and having a flange overlying one. end of the collar, said collar having recesses formed therein and the liner having projections extending into said recesses to prevent relative movement of the collar and liner.

5. In a device of the class described, a Iporcelain collar having an unthreaded bore and a threaded metallic liner snugly fitting Within and anchored in said collar and having a fiange overlying one end of the collar, said liner flange having a portion inter-engaged With the end of the collar and the liner being .inter-engaged adjacent its other end With the collar Within the latter to prevent relative `n'iovenient of' the collar and liner.

6. In a device of the class described, an

kannnlar collar of porcelain having an un JOHN WEBER. 

